1. Field of the Invention
The present invention relates to a method for homing onto a target which is detected forwardly sideways offset from the glide trajectory of a projectile which is equipped with a search head, with control surfaces and with horizontal glide surfaces, through the implementation of a roll motion for the yaw maneuver.
2. Discussion of the Prior Art
A method of that type has been known from the disclosure of U.S. Pat. No. 3,695,555, which is directed to an artillery projectile or missile which is guidable during its final flight phase; or from the disclosure of British Pat. No. 1,605,007 for a projectile in the configuration of a target-tracking torpedo. However, the invention especially relates to projectiles which are guidable during their final flight phase, as is known from the disclosure in DEFENSE ELECTRONICS, Volume of June 1984, page 102, as an article of subordinate ammunition or submissile.
The simplest conditions for the maneuverability of such a projectile, considered from the standpoint of guidance technology, are obtained when a crossed pair of tail guidances or control surfaces has associated therewith a similarly crossed pair of substantially larger gliding wings or surfaces which are arranged opposite the control surfaces. Inasmuch as the firing or the start of the projectile cannot be implemented with extended control or guidance surfaces and gliding surfaces because of constructive reasons, while on the other hand, a limitation in the caliber for the design of the projectile and the spatial requirement for the warhead and target-tracking control installations, do not render available the space which is necessary for the retraction of large gliding wings, whereas the desirably large aerodynamic gliding flight ability cannot be attained with only small gliding wings or surfaces, in projectiles pursuant to the present invention, one must be satisfied with horizontal gliding wings of preferably the type under consideration.
As is explained in detail hereinbelow in conjunction with FIG. 1 of the drawings, in view of the lack of vertically oriented gliding wings or surfaces, the maneuverability in the yaw direction (in essence, in a sideways or lateral displacement of the longitudinal axis of the projectile) out of an actually given flight position, is considerably restricted. For homing onto a sideways or laterally offset target, this resultingly necessitates a displacement of the lift vector from the vertical into a direction towards the forwardly sideways offset target, which requires a correspondingly intense roll movement of the projectile about its longitudinal axis. However, inasmuch as such a projectile does not represent a body which is symmetrical with regard to its aerodynamic flow properties, every change in the roll position produces reactions over other aerodynamic influences, and thereby undesirable reactions on the flying behavior. These reactions are not linear in nature, and are particularly intense at large roll angles; which requires excessively large demands on the controls for the actuation of the individual components which are critical for the flight, in order to be able to carry out a predetermined maneuver which is stable in flight. However, during transition from a rapid gliding flight motion into a steep descending path for homing onto an acquired target, there are required particularly sharp or severe course maneuvers, which can easily lead to deflections out of the stable flight pattern; such that the motion of the projectile will no longer listen to the guidance and the target can be missed.